GB2240084A

GB2240084A - Improvements in or relating to load handling

Info

Publication number: GB2240084A
Application number: GB9000253A
Authority: GB
Inventors: Colin Ashton
Original assignee: FIELDEN ENGINEERS Ltd
Current assignee: FIELDEN ENGINEERS Ltd
Priority date: 1990-01-05
Filing date: 1990-01-05
Publication date: 1991-07-24
Also published as: GB9000253D0

Abstract

Arms 20 of a grab are moved towards each other to grip opposed elongate sides (28 and 30) of a stack of slabs comprising a load. The grab and load are then raised and the jaws 16 and 18 are pivoted about an axis 32 through 90 DEG , The grab is then lowered such that the stack is supported on the downwardly facing surface 33 of the lowermost slab 29. Rotation is via a rack (34) and gear drive. The grab can be used with a delivery lorry crane. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO LOAD HANDLING.

The present Invention relates to load handling apparatus and to a method of reorientating a load.

When selling concrete flags, pavers or stones from a garden centre, for instance, a block of such flags, pavers or stones is taken from a lorry and deposited on the floor with the flags being stacked side by side, as they were on the lorry. When some of the flags are removed, those remaining tend to fall into the vacated space thereby damaging the flags and looking untidy. The flags may also be a risk to customers or staff if they should fall on them.

According to one aspect of the present invention, a method of reorientating a load comprises moving opposed members relative to each other towards each other to engage opposed port Ions of the load which extend upwardly with a first portion of the load facing downwardly, and then moving the members and the load until a second portion of the load, different from the first portion, faces downwardly, with the opposed portions of the load engaged by the members still extending upwardly, and then releasing the members from the load.

The method may comprise raising the members after the load has been engaged and, alternatively or additionally, the method may comprise lowering the members when the second portion of the load has been moved such that it faces downwardly. The method may comprise moving the location of the load after the members have engaged the load, either before or after or during reorientation.

The method may comprise pivoting the members in order to reorientate the load and the pivot axis may extend between the members.

The method may comprise the load initially being supported on the first portion, and then, subsequent to reorientation, being supported on the second portion.

The load may initially comprise a plurality of side by side articles and the method may comprise reorientating the load to a position in which the articles form an upwardly extending stack of articles.

The method may comprise the members engaging opposed portions of each article.

According to another aspect of the present invention, load handling apparatus comprises a support including a pair of members movable relative to each other in a direction towards or away from each other and arranged to engage opposed portions of a load which extend upwardly with a first portion of the load extending downwardly, the members being movable when they so engage a load such that a second portion of the load extends downwardly with the opposed portions of the load engaged by the members remaining upwardly extending.

The members may be pivotal ly mounted on the support about an axis extending between the members, and driving means may be arranged to act on at least one of the members in order to maintain that member or return that member to a set pivotal position.

Either or both of the members may be pivotally or translationally movable towards or away from the other member.

The members may include means for engaging opposed surfaces of each of a plurality of articles comprising the load.

The present Invention also Includes load handling apparatus as herein referred to when used in a method of reorientating a load as herein referred to.

The present invention may be carried into practice In varlous ways, but several embodiments will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a front view of a grab 10; Figure 2 is a side view of the grab shown in Figure 1; Figure 3 is a perspective view of a block 12 of slabs 14 in a first orientation, and Figure 4 is a perspective view of the block 12 shown in Figure 3 in a second orientation comprising a stack of the slabs 14.

As shown in Figures 1 and 2, the grab includes a pair of opposed Jaws 16 and 18 each mounted on respective arms 20 and 22. The arms 20 and 22 extend, at their upper ends, inwardly towards each other into a housing 24, and the housing 24 Is provided with a swivel 26 from which the grab may be suspended. Hydraulic lines (not shown) may be provided in order to power the grab, as described below.

The arms 20 are movable towards or away from each other by means of hydraulic Jacks (not shown) connected between the arms and the housing. Although in the illustrated embodiment, the Jaws are shown as being transiatlonally movable relative to each other. In an alternative embodiment the Jaws are pivotally movable relative to each other.

The stack initially rests on the downwardly facing surface 27 of each of the slabs 29. In use, the grab is raised and located by the swivel 26 over a block 12 lying in the position shown in Figure 3. The arms 20 and 22 are brought towards each other until the jaws 16 and 18 grip opposed elongate sides 28 and 30 of the block.

The grab and the gripped block are then ralsed by the swivel and the jaws 16 and 18 are then pivoted about an axis 32. To this end the jaws are each pivotally mounted on their respective arms such that they can undergo 900 of relative movement in the anti-clockwise direction from the position shown in Figures 1 and 2.

When the jaws have been pivoted through 900 the block is located in the orientation of the stack shown in Figure 4.

The stack and grab are then manouevered into the required position and lowered by the swivel when the arms 20 and 22 are moved away from each other to release the grip on the block 12 with the block resting on the downwardly facing surface 33 of the lowermost slab 29.

The grab can then be swung away from the block in order to repeat the operation on a further block.

When the Jaws are being pivoted it can be seen that the elongate dimension of the block is reorientated from extending along to extending upwardly and that thus there must be a significant clearance between the elevation of the Jaws and the higher elevation of the housing. An Indicator (not shown) may be provided extending downwardly from the housing which is arranged to be contacted by the pivoting block to alert the operator that there may be insufficient clearance to enable the reorientation or pivotal movement to be completed.

In order to effect the pivotal movement of the jaws 16 and 18, it may only be necessary to power one (or both) of the Jaws 16 or 18, and that power may be provided by a gear box and an hydraulic motor (not shown) or a rack and pinion gear arrangement 34 or an hydraulic cylinder (not shown). When a block 12 has been reorientated as described above, the Jaw 16 can be powered pivotally back to the position shown in Figures 1 and 2 and the other Jaw 18 can be loaded by a spring 36 such that, when it no longer grips the block, it automatically pivots back to the position shown in Figures 1 and 2.

The block 12 is extremely heavy and, as the grab is suspended by a swivel, it Is necessary that the Jaws 16 and 18 pivot about generally the centre of gravity of the block.

it is also desired that the opposed Jaws grip each of the slabs 40 in the block: Although the block is likely to be enveloped by shrink wrap plastics it is of use to ensure that the slabs do not si ide relative to each other during the reorientation. To this end, each of the jaws is provided with elongate grips 38 which are located one above the other when vlewed in Figures 1 and 2. As a result of the flexibility of the jaws, and the large gripping force required, the grips 38 may be concave when In their relaxed position, with the outer ends of the grips 38 away from the pivotal connection flexing outwardly away from the opposed Jaw during gripping to ensure a generally even grip along the length of the block.

Alternatively or additionally a series of individual grips may be provided along one or both Jaws or which may be movable separate from each other to each grip a slab, and those individual grips may be powered such that opposed grips can each apply a predetermined gripping force to opposed sides of each slab.

Alternatively the individual grips may be provided with resilient resistance such that each grip securely engages a slab. Alternatively or additionally the grips may include castellated formations for instance on rubber in order to enable the gripping portions on the jaws to provide the required deflection to grip, and the castel lations may vary in location and shape as the distance from the pivot varies. Where the term individual is used in this paragraph it is intended to cover groups of two or more slabs.

Claims

1. A method of reorientating a load comprising moving opposed members relative to each other towards each other to engage opposed portions of the load which extend upwardly with a first portion of the load facing downwardly, and then moving the members and the load until a second portion of the load, different from the first portion, faces downwardly, with the opposed portions of the load engaged by the members still extending upwardly, and then releasing the members from the load.

2. A method as claimed in Claim 1 comprising raising the members after the load has been engaged.

3. A method as claimed in Claim 1 or 2 comprising lowering the members when the second portion of the load has been moved such that it faces downwardly.

4. A method as claimed in any preceding claim comprising moving the location of the load after the members have engaged the load.

5. A method as claimed in Claim 4 comprising moving the location of the load before reorientation.

6. A method as claimed in Claim 4 comprising moving the location of the load after reorientation.

7. A method as claimed in Claim 4 comprising moving the location of the load during reorientation.

8. A method as claimed in any preceding claim comprising pivoting the members in order to reorientate the load.

9. A method as claimed in Claim 8 in which the pivot axis extends between the members.

10. A method as claimed in any preceding claim comprising the load initially being supported on the first portion and then, subsequent to reorientation, being supported on the second portion.

11. A method as claimed in any preceding claim in which the load initially comprises a plurality of side-by-side articles.

12. A method as claimed in Claim 11 comprising reorientating the load to a position in which the articles form an upwardly extending stack of articles.

13. A method as claimed in Claim 11 or 12 comprising the members engaging opposed portions of each article.

14. A method of reorientating a load substantially as herein described with reference to, and as shown in the accompanying drawings.

15. Load handling apparatus comprising a support including a pair of members movable relative to each other in a direction towards or away from each other and arranged to engage opposed portions of a load which extend upwardly with a first portion of the load extending downwardly, the members being movable when they so engage a load such that a second portion of the load extends downwardly with the opposed portions of the load engaged by the members remaining upwardly extending.

16. Apparatus as claimed in Claim 15 in which the members are pivotally mounted on the support about an axis extending between the members.

17. Apparatus as claimed in Claim 16 including driving means arranged to act on at least one of the members in order to maintain that member, or return that member, to a set pivotal position.

18. Apparatus as claimed in any of Claims 15 to 17 in which at least one of the members is pivotally movable towards or away from the other member.

19. Apparatus as claimed in any of Claims 15 to 18 in which at least one of the members is translationally movable towards or away from the other member.

20. Apparatus as claimed in any of Claims 15 to 19 in which the members include means for engaging opposed surfaces of each of a plurality of articles comprising the load.

21. Load handling apparatus substantially as herein described with reference to, and as shown in the accompanying drawings.

22. Load handling apparatus as claimed in any of Claims 15 to 21 when used in a method of reorientating a load as claimed in any of Claims 1 to 14.